shiboken2: Handle default parameters of const pointers

Occurs in Qt 6:

QKeyEvent(..., const QInputDevice *device = QInputDevice::primaryKeyboard());

We need a const-cast here since shiboken needs a QInputDevice * for type
conversion.

Change-Id: Iea1137eac44a26b7bc9cf0e1908c0e42ba2de39f
Reviewed-by: Christian Tismer <tismer@stackless.com>

3 files changed, 19 insertions, 2 deletions

diff --git a/sources/shiboken2/generator/shiboken2/cppgenerator.cpp b/sources/shiboken2/generator/shiboken2/cppgenerator.cpp
index b071ae181..65e12c7bc 100644
--- a/sources/shiboken2/generator/shiboken2/cppgenerator.cpp
+++ b/sources/shiboken2/generator/shiboken2/cppgenerator.cpp
@@ -2424,8 +2424,17 @@ void CppGenerator::writePythonToCppTypeConversion(QTextStream &s,
         s << ' ' << cppOut;
     } else if (treatAsPointer || isPointerOrObjectType) {
         s << " *" << cppOut;
-        if (!defaultValue.isEmpty())
-            s << " = " << defaultValue;
+        if (!defaultValue.isEmpty()) {
+            const bool needsConstCast = !isNullPtr(defaultValue)
+                && type->indirections() == 1 && type->isConstant()
+                && type->referenceType() == NoReference;
+            s << " = ";
+            if (needsConstCast)
+                s << "const_cast<" << typeName << " *>(";
+            s << defaultValue;
+            if (needsConstCast)
+                s << ')';
+        }
     } else if (type->referenceType() == LValueReference && !typeEntry->isPrimitive() && isNotContainerEnumOrFlags) {
         s << " *" << cppOut << " = &" << cppOutAux;
     } else {
diff --git a/sources/shiboken2/generator/shiboken2/shibokengenerator.cpp b/sources/shiboken2/generator/shiboken2/shibokengenerator.cpp
index 6abaef698..43ebefe14 100644
--- a/sources/shiboken2/generator/shiboken2/shibokengenerator.cpp
+++ b/sources/shiboken2/generator/shiboken2/shibokengenerator.cpp
@@ -1145,6 +1145,12 @@ bool ShibokenGenerator::visibilityModifiedToPrivate(const AbstractMetaFunction *
     return false;
 }
 
+bool ShibokenGenerator::isNullPtr(const QString &value)
+{
+    return value == QLatin1String("0") || value == QLatin1String("nullptr")
+        || value == QLatin1String("NULLPTR") || value == QLatin1String("{}");
+}
+
 QString ShibokenGenerator::cpythonCheckFunction(const AbstractMetaType *metaType, bool genericNumberType)
 {
     QString customCheck;
diff --git a/sources/shiboken2/generator/shiboken2/shibokengenerator.h b/sources/shiboken2/generator/shiboken2/shibokengenerator.h
index d8259d245..da0c16851 100644
--- a/sources/shiboken2/generator/shiboken2/shibokengenerator.h
+++ b/sources/shiboken2/generator/shiboken2/shibokengenerator.h
@@ -301,6 +301,8 @@ protected:
 
     static bool visibilityModifiedToPrivate(const AbstractMetaFunction *func);
 
+    static bool isNullPtr(const QString &value);
+
     QString converterObject(const AbstractMetaType *type);
     QString converterObject(const TypeEntry *type);